Good morning. The well documented shift towards wet and windy conditions developing over the UK over the next week is well under way but how long will it last?

Plenty for you posters to discuss this morning mostly reflecting that question I would guess. So here is this morning's report released to my website today.

HERE IS MY LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY FRIDAY OCTOBER 3RD 2014.

NEXT UPDATE SATURDAY OCTOBER 4TH 08:00

THE CURRENT GENERAL SITUATION. An active cold front will move slowly but steadily SE across all of the British Isles over the coming 24-36 hours with a strong SW flow ahead of it veering West to NW behind the front.

MODELS-2 WEEK HEADLINE All areas look like being unsettled and windy with rain at times in cool conditions. Possibly becoming drier and less cool later especially in the South.

THE JET STREAM ENSEMBLE FORECAST A change in the position and orientation of the Jet stream is still shown as it exits Newfoundland and eventually Canada, crosses the Atlantic and over Southern Britain next weekend. It then dips sharply South over the Atlantic and back North to lie well North of NW Europe in the 10-14 day period.

GFS The GFS operational splits into two halves with Week 1 showing the well documented slide into wet and windy conditions as Low pressure over or to the NW of the UK dominates conditions across all areas. This is followed by a switch to High pressure, firstly crossing the UK and then moving into Europe and extending a ridge back West across the UK with fine and dry weather with mist and fog night and morning becoming the main features of the weather in continuing cooler conditions than of late.

THE GFS ENSEMBLES. The GFS Ensembles are broadly similar in this resolve bringing drier and brighter weather back across the UK slowly through week 2 as the Jet flow returns North of Europe but a way South over the Atlantic in week 2. So a wet and windy week next week should slowly give way to less rain, calmer and quieter conditions again through the second week especially across the South and East.

UKMO UKMO this morning maintains a deep Low complex close to or over the UK through the middle days of next week with frequent outbreaks of rain or showers, heavy at times in a generally cyclonic SW flow across the UK.

THE FAX CHARTS The Fax Charts show an active and squally cold front crossing SE over the UK over tonight and Saturday with squally winds and heavy rain for a time. A ridge is then shown to give a quieter interlude across the South briefly before Low pressure and active troughs move in from the West with the active troughs crossing East over all areas to start next week with gales and heavy rain and showers for all, the longer spells of rain most likely across the South.

GEM The GEM operational brings unsettled, often windy and wet conditions across the UK next week as Low pressure becomes deep and extensive close to or over Northern Britain with any improvements very slow as it only edges away slowly to the NE later filling slowly with higher pressure and drier conditions edging up across the UK from the SW next weekend and beyond.

NAVGEM NAVGEM today is equally unsettled next week as a deep Low close to the UK brings spells of rain or heavy showers to all areas on most days. Pressure is also shown to rise slowly late in the week as the Low to the North fills though rain at times is still likely for most.

ECM The ECM operational maintains the basic theme of all other output in bringing a deep Low down towards and over the West of the UK next week with rain and wind at times for all. With the thrust of Low pressure only slowly edging away North later and some reinforcements shown to move up from the SW next weekend there looks less signs of High pressure becoming as dominant later as it's counterpart models with further rain and showers at times possible almost anywhere right out to Day 10.

NOTABLE TREND CHANGES FROM PREVIOUS RUNS There is a slow growth in the theory of better conditions under High pressure returning to the UK in some shape or form after a week to 10 days of the coming unsettled and windy period.

MY THOUGHTS Low pressure is going to be the main ingredients of the weather over the next week with all models supporting deep Low pressure moving down close to the West and North of the UK with spells of heavy rain and showers for all next week in temperatures much more seasonably average than of late, the feel accentuated by the wind. It's what happens thereafter which has shifted a little this morning towards at least a chance that drier and more benign weather could return over next weekend and beyond as High pressure rebuilds from the SW in response to a shift North of the Jet again over and to the East of the UK. The ECM model is less supportive of this theory and brings further Low pressure up over the UK from the warm waters to the SW with further rain at times to end it's run this morning and while I sense that there is a reasonable chance of improvements in conditions being viable there is a lot of ingredients over the Northern hemisphere next week which have to come together for that to happen and I feel we will see plenty of swings towards and away from better weather shown during the course of the output released over the unsettled and Autumnal period of the next week. One thing that is a given should any better weather develop after next weeks wet period it is unlikely we will see particularly warm weather return as with wet surfaces by then mists and fogs under any High pressure could become a major issue along with the seasonal increase in the incidence of frosts should skies clear. So today looks the last day that any outside tidying of gardens etc ready for the Winter can be accomplished unhindered by weather factors.

Thanks, Martin - though I don't know about tidyong gardens for winter. We are still in full growth down here!

My garden is still in flower due to the persistent warmth of the autumn so far.

HERE IS MY LATEST TEXT ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY SATURDAY OCTOBER 4TH 2014.

NEXT UPDATE SUNDAY OCTOBER 5TH 08:00

THE CURRENT GENERAL SITUATION. An active cold front will clear East out of Britain today followed by a ridge of High pressure over the South later. Later still sees a deep Low move SE towards Western Britain with a strengthening SW flow later tomorrow.

MODELS-2 WEEK HEADLINE All areas look like being unsettled and windy with rain at times in cool conditions. Possibly a little drier and less cool in the SE later.

THE JET STREAM ENSEMBLE FORECAST The change in positioning of the Jet flow is currently under way. It will settle blowing strongly across the Atlantic towards Southern England and the English Channel over the next week or so with somewhat more variability shown in week 2 though generally maintaining a latitude well South of recent levels, certainly over the Atlantic and NW Europe.

GFS The GFS operational today shows a deep Low move down from the NW towards a point NW of ireland and then moves slowly NE late next week filling slowly. This will deliver quite a few days of windy and unsettled weather with spells of rain and showers for all. A quieter interlude then develops though still rather unsettled but with lighter winds bext weekend before Week 2 sees a return to wet and windy conditions in strong SW winds across the UK with deep Low pressure anchored to the NW.

THE GFS ENSEMBLES. The GFS Ensembles are broadly similar with much unsettled weather over the next few weeks. It does show a different scenario in Week 2 in that Low pressure is further South over the Atlantic later with a large and warm High pressure over Eastern Europe pumping some of that warm air North across Britain late in the period with most of the rainfall by then across the West.

UKMO UKMO this morning has deep Low pressure near Western Ireland on Wednesday gradually transferring NE over the following 48 hours. This means that the weather across the UK will be very unsettled and wet at times with spells of rain and showers in strong winds too, all gradually becoming less pronounced towards the end of the week as the Low fills and moves away to the NE.

THE FAX CHARTS The Fax Charts show a complex zone of Low pressure developing just to the West of the UK next week. This is shown to be slow moving and throwing troughs of Low pressure East and NE across the UK regularly in cool and often blustery weather with showers and longer spells of rain for all areas, the latter most likely towards the South.

GEM The GEM operational looks very Autumnal this morning with the deep Low pressure next week very slowly drifting North late in the week but only at the expense of a new centre moving in to replace it to maintain a Low complex close to the North with Westerly winds and rain and showers for all at times throughout the run.

NAVGEM NAVGEM is also slow to remove Low pressure away from the UK later next week with the centre still over Scotland quite late next week with further Low pressure out in the Atlantic and a trough to the SW keeping the unsettled theme going beyond the period albeit not quite as windy as early next week.

ECM The ECM operational maintains the basic theme of all other output in bringing a deep Low down towards and over the West of the UK next week with rain and wind at times for all. With the thrust of Low pressure only slowly edging away North later and further Low pressure up to the NW driving further strong SW winds and rain across the UK late in the run there is little respite from the unsettled period apart from the thrust of the heaviest rain reverting towards the North and West later with some warmer winds affecting the South and East later.

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trend towards better weather in week 2 shown in yesterdays 00zs has been reversed somewhat this morning.

MY THOUGHTS We are currently entering the first spell of seriously Autumnal weather across the UK this season as Low pressure becomes the driving force to the weather over the next couple of weeks. In the short term a deep Low looks very likely to be close to Western and Northern Britain for much of next week with plenty of rain and showers for all in blustery and much cooler conditions than of late. Most output then only shows slow moderation in these conditions as the Low fills and drifts slowly away North or NE. This still appears to leave an unstable if lighter Westerly flow with further rain in places before further Atlantic Low pressure rolls over from the West, probably on a slightly more Northern aspect bringing the heaviest rain and strongest winds to more Northern and NW areas with the South and East experiencing a chance at least of something a little drier and less cool as milder SW winds set up. The Jet Stream though seems to heave ratcheted up a copuple of gears over recent runs and this throws the risk of some active Low pressure areas at times throughout the next few weeks with the exception of a temporary reduction in strength next weekend. With High pressure sending some very warm air at times across Europe in the second week and the comparative cool Autumn air to the NW of Britain a spell of notably wet and windy weather in Week 2 looks possible over the higher ground of the North and West as the warm South or SW flow over the UK engages with the cooler air to the NW and gives rise to an active waving frontal zone somewhere over the UK. Something to watch for certain in week 2. However, having said all of this despite temperatures much lower than of late there is no distinctly cold weather on offer from the models today and it may well be that the South and East see above average temperatures return again if the moist SW or South flow develops in week 2 as hinted at this morning.

The idea that the Atlantic 'storm train' might take a break next week, as a few of the models were suggesting in the 8-10 day range, has been well and truly put down over the past two days.

The main reason is visible on the day 6 ECM 00z op run chart:

The area of low pressure SW of Greenland was originally held back further west, allowing the cold air on the western flank of the UK storm system to push further south and develop a secondary LP, while a ridge developed near Greenland and prevented the western low from making much progress into the Atlantic. We were then left with the UK storm system slowly decaying while the secondary LP threatened to drift NE and bring a lot of rain.

Now, that LP to the SW of Greenland is being shown to make more progress, cutting off the feed of cooler air south in the mid-Atlantic, and redirecting any new LP development on an easterly track. This essentially means the jet is aimed back at the UK again.

It may then be a question of how far NW the next Atlantic storm tracks, with ECM opting for a NW/SE split in 10 days time:

GFS has the LP further SE than this, with a very autumnal outlook persisting until about a fortnight from now.

Despite this, temperatures might do fairly well from around Wednesday next week, with maximums of 16-18*C and minimums of 8-12*C, so out of the rain, it could feel quite reasonable.

Finally we can put Summer to bed

Its been a good run for you warm weather fans. Hopefully a lively Autumn followed by a cold winter will follow

A northerly blast appearing on high res, and its late enough in the year for that to mean something. Will be watching this very closely.

I've heard that  at the beginning of September and look what happened!

A northerly waft maybe... room for that to evolve into something more but ECM's having none of it.

I think I'll just sit back this weekend and see if the models can get to grips with the unstable situation in the mid-Atlantic next week - at this stage the models can't seem to figure out how the first of the large low pressure systems makes its exit.

Well I guess its time to watch these things because given the right pattern its not too early...

The last memorable time it happened was of course 2012 (below).

If this doesn't turn out to be a model ghost I will become very active on this thread in the coming weeks.

The 18Z is much further west than the 12Z though. We should bear in mind that everything tends to work out much further east than progged. I'm really not trying to ramp, but this synoptic does interest me as I guess everyone has long since worked out, so I will be watching it. I'm looking for that sweat spot when the LP is in exactly the right place that when it clears east we have the best possible exposure to the arctic airmass. 

This is pretty damn good as far as runs go, note the heights over greenland, the secondary low also looks to be helping a more direct flow of cold air. Hopefully we could have some sunny days and frosty nights. 

What's going on here then? A large shift SW in the main core of the low pressure complex on the GFS 18z compared to the 12z.

The run goes on to avoid much of a northerly by quickly bringing in further LP from the west, which leads to an unsettled FI, initially with LP in line with the UK, then with LP further west, which increases temperatures but increases potential rainfall amounts.

October's looking like a soggy one at this stage, even if the LP locates more to the NW from earlier on in time as per the ECM 12z op run.

I was struck by your statement in bold as it appears you're talking about all cases with all patterns, but on the other hand you might only be referring to when there's HP or blocking highs to the NW or W.

The latter ties in with what I can recall with regard to many northerly outbreaks over the years, often causing an exciting Arctic blast laden with instability to become a laid-back waft of cold air with stable conditions keeping snowfall at bay.

By contrast, when blocking is to the east or northeast, everything tends to work out further west than progged at the 6-8 day range. That one is easily attributed to blocking highs being shifted east or flattened too readily, but the case with northerly outbreaks is somewhat less clear. Perhaps it is simply that the strength and size of the HP to the NW or W tends to be underestimated at that range. Or perhaps their ability to fend off low pressure systems developing in the unstable sector of cold air outbreaks.

These characteristic errors are what keep NWP model watching so very entertaining and hard to anticipate at times. Last winter I kind of missed having to watch a promising northerly as it creeped towards the reliable timeframe, hoping to see it holding together far enough west... that's part of what makes the silly season so silly!

ECM nearly gives us our first proper cold weather but the northerly just misses. Scotland does get some -5c air though.

http://www.wetterzentrale.de/pics/Recm1681.html

http://www.wetterzentrale.de/pics/Recm1922.html

How does copyright work with Wetterzentrale can we post them on this forum or can we just supply the link?

HERE IS MY LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY SUNDAY OCTOBER 5TH 2014.

NEXT UPDATE MONDAY OCTOBER 6TH 08:00

THE CURRENT GENERAL SITUATION. A ridge of High pressure will move away East out of Southern England with a strengthening Southerly flow ahead of an active cold and occluded front East across the UK tonight and tomorrow.

MODELS-2 WEEK HEADLINE  All areas look like being unsettled and windy with rain at times in cool conditions. Possibly a little drier and less cool in places later.

THE JET STREAM ENSEMBLE FORECAST The Jet Stream will remain in it's new Southern location near Southern England through this week before becoming more broken and ill defined on this side of the Atlantic through Week 2 though still with the strongest section in the West Atlantic heading towards quite Southerly latitudes.

GFS The GFS operational today shows a deep Low moving down from the NW to a point just to the west of Ireland and then drifting it slowly NE later in the week but maintaining a trough back across the UK with increasingly cold air by next weekend. It then shows pressure gently recovering through Week 2 especially towards the North and East while SE winds and troughs affect Southern and Western Britain for a time. High pressure is then shown to centre near Northern Britain at the end of the run with cool, Autumnal and possibly mist conditions developing for many.

THE GFS ENSEMBLES. The GFS Ensembles are broadly similar in theme with this weeks Low being replaced by High pressure over the UK through the start of Week 2 before strong SE winds and rain in association with deep Low pressure to the SW brings a return to wet and windy conditions late in the period.

UKMO UKMO this morning has deep Low pressure near Northern Ireland on Thursday moving steadily away NE and filling but maintaining a broad and open trough over the UK with cool and showery weather continuing as a result leading into the weekend.

THE FAX CHARTS  The Fax Charts show a complex zone of Low pressure well in control of the weather over the UK through most of this week. The centre just to the West of the UK is shown to throw frequent troughs East across the UK with spells of wind, rain and showers for all through all weekdays in rather cool conditions overall.

GEM The GEM operational today looks like staying very unsettled over the next 10 days with rain and strong winds featuring regularly as this weeks Low pressure moves away NE next weekend and becomes replaced by a strong Westerly flow over the Atlantic in association with more deep Low pressure near NW Britain at the start of week 2.

NAVGEM NAVGEM is also slow to remove Low pressure away from the UK later in the week finally bringing a brief ridge of High pressure across over next weekend with reducing amounts of showers as it does. Temperatures overall are shown close to or a little below the average. 

ECM The ECM operational is rather similar to GEM this morning in not supporting much of a ridge following this weeks Low. Instead it rolls in more deep Low pressure across the Atlantic with more gales and rain affecting all areas at the start of the second week.

NOTABLE TREND CHANGES FROM PREVIOUS RUNS Mixed messages remain the trend between the models today with the split between more mobile, windy and wet weather in week 2 challenged by quieter Anticyclonc conditions for a time by some other output.

MY THOUGHTS  Rather mixed output this morning in the longer term though we have 100% agreement on the course of events this week with a deep Low close to Western England early in the week tracking slowly NE later and filling while maintaining showers and longer spells of rain across the UK reducing somewhat by next weekend. There will be some strong winds at times especially near the coasts but these should die down later as some rather cool air filters down from the North. This is where the models differ with GFS in particular illustrating a shift towards High pressure and calmer Autumnal weather at least for a time before Low pressure to the SW becomes influential by the end of it's run. GEM and ECM though show a much more disturbed pattern being maintained through Week 2 as more deep Low pressure and attendant strong winds run in from the West to keep wind and rain very much a feature out to the end of the run. Which is right is hard to say at the moment but my money would be towards the thoughts of ECM as very cold air sliding South across the Norwegian Sea next weekend is likely to engage with milder Atlantic air setting up a new surge of deep Low pressure and spells of rain at times through the following week as we dip deeper into Autumn.

A shame that most of next week is looking set to be a bit s**t with unsettled and often windy weather for most parts. Although having said that, it won't be ALL bad where there'll be some sunshine knocking about between the more showery stuff. Can't complain about poor air quality as well.

Don't forget to keep an eye on the northern hemisphere view as we head through the autumn:

http://www.theweatheroutlook.com/twodata/datmdlout.aspx

Very 

HERE IS MY LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY MONDAY OCTOBER 6TH 2014.

NEXT UPDATE TUESDAY OCTOBER 7TH 08:00

THE CURRENT GENERAL SITUATION. An active trough will cross steadily East over the UK today with an unstable and showery WSW airflow following on behind across England and Wales.

MODELS-2 WEEK HEADLINE  All areas look like being unsettled and windy with rain at times in cool conditions. Possibly a little drier and less cool in places later.

THE JET STREAM ENSEMBLE FORECAST The Jet Stream remains focused across the Atlantic to be over or to the South of the UK keeping all parts in the cool and unsettled trough like structure for the next week or so. After a brief lull in this early next week the flow re-strengthens strongly across Central UK tiwards the end of the period.

GFS The GFS operational today offers a very unsettled and changeable period of weather over the next two weeks. This week's deep and slow moving Low gradually clears away NE next weekend leaving a slack and unstable flow from the West across the UK for a time before more Low pressure delivers more rainfall next week, gradually transferring more towards Northern and Western parts with gales as by the end of the run a deep Low pressure crosses East just to the North of the UK.

THE GFS ENSEMBLES. The GFS Ensembles are supportive of the operational in Week 1 with better improvements shown towards the South and East for a time next week as pressure builds temporarily from the South and East. This is then replaced by more Low pressure again moving into the UK from the West to end the run with a return to wind and rain at times for all in blustery West or SW winds.

UKMO UKMO this morning keeps a Low pressure belt stretching from the UK to Scandinavia next weekend with further rain at times especially over the South. It will feel cool too though wind strengths will of become less strong by then.

THE FAX CHARTS  The Fax Charts continue a very disturbed and complex synoptic pattern all revolving around a deep Low just to the West of the UK by midweek. A series of troughs will affect the South most with heavy showers and more prolonged rainfall at times, some heavy. By the start of next weekend the Low is shown to begin to fill and drift slowly away NE.

GEM The GEM operational today looks very Autumnal with little cessation of Low pressure close to or over the UK bringing repeated periods of rain and showers in sometimes cool conditions lasting throughout the next 10 days as the Jet Stream remains further South than normal.

NAVGEM NAVGEM gradually takes the deep Low of this week gradually NE by next weekend with winds decreasing away and leaving drier and brighter conditions with a few showers at the weekend as pressure steadily rises. 

ECM The ECM operational shows a muted improvement at the weekend as the current deep low pressure zone finally fills and moves away NE. It isn't long though before more Low pressure moves in towards the NW with troughs sweeping East across the UK with more wind and rain for all at times next week.

NOTABLE TREND CHANGES FROM PREVIOUS RUNS No real change from the previous trends of recent runs is shown today.

MY THOUGHTS  The thoughts of the models this morning seem generally supportive of the now more Autumnal type weather pattern under Atlantic Low pressure now continuing largely unchallenged over the next few weeks. There are as always exceptions to this general pattern and it looks like early next week may see a period of rather better weather towards the South and East for a time as pressure builds towards the South and East of the UK. This is by no means a guarantee and is generally chased away anyway by more unsettled and windy weather by the end of next week from those models that show such an improvement. Rainfall amounts will be varied but could be large locally as active troughs pass through or any local heavy showers occur this week. Winds will sometimes be strong especially midweek and perhaps again later next week but a quieter period looks very likely over next weekend. Temperatures though of course lower than of late may end up close to average overall with the coolest conditions within the areas of persistent rain and the warmest weather towards the SE later this week and perhaps again for a time next week though probably tempered by a strong SW breeze then. Fog and frosts will be generally restricted by often too much cloud and breeze so shouldn't be  a major issue through the period. So all in all a typical changeable Autumn period of weather to come for all areas but away from the local wind gusts and downpours I can see nothing particularly noteworthy or disruptive on a nationwide level over the period.

GFS is keen on developing an area of low pressure to the SW of the UK and having it drift slowly NE or N, potentially bringing a few warmer days for the SE in particular but also a risk of large rain amounts, depending on how far west the system forms and travels.

Thing is... ECM has no such feature and has been persistent with this version of events for a few runs now, where a slack westerly flow introduces a slightly cooler setup for the weekend (compared to Wed-Fri this week), before a new area of low pressure develops south of Greenland and exerts some influence on us - though not without high pressure across Europe providing a little resistance:

This theme of a setup bringing very mild conditions, but with unsettled weather persisting across the NW in particular, is also seen on the GFS 00z and 06z runs. It depends on the jet digging south enough in the central North Atlantic, and GEM shows the consequences if that doesn't happen - the jet fires more storms right through the UK instead.

There's a risk of some very stormy conditions at times if the jet packs a punch but comes up against a strong high pressure belt across Europe as well. That's too far away to be concerned about at this time, though.

Things are really getting interesting. Its a tall order but there is a potential here for some early wintry weather provided the angle of attack is perfect (I'd put it at somewhere near 1/8), the 6Z GFS had it going to close to scandanavia where some unusually early cold pooling under high pressure took place including sub zero maxima at the surface.

The ECM arguably gets somewhat closer:

The LP to the west cuts off the cold air before it can get to the UK, however the position of the low is still up for debate and a shift to a weaker more southerly position is a pretty common correction (however the entire pattern shifting east is also very common). 

Just to add a little balance, the above is really grasping at straws for some reason. The outlook looks overwhelmingly unsettled and rather average for the time of year. Well it is early October...

I did say 1/8! But it really isn't too early, if anything the 2012 cold spell in late october was overkill, granted it takes something even more special to get it in mid October.

In fact the 2012 event wasn't even perfect, the HP is too far east for a direct attack, yet even this was enough to bring -8C uppers as far south as wales and snow showers as far south as Yorkshire. And snow showers in mid october in the Northern isles is downright common, happening every couple of years or so.  

To be clear to everyone (especially the guests): I am not forecasting wintry weather, and the charts do not give that implication (90% chance itl come to literally nothing). All I am saying is that the potential does exist, and that it is something worth keeping an eye on until the more reliable timeframe.